Dan Hicks, DVM, MS, DACVIM (Neurology/Neurosurgery)

Veterinary Neurology & Neurosurgical Specialists

1. Clinical features

2. Anatomic localization

3. Differential diagnosis

4. Plan

Clinical Neurology:

A

B

Differential Diagnoses: dependent on where, when (acuity), what (signalment)

Exam tells us where not what!

T3L3 S1

C1-C5

Infratentorium

Supratentorium

Peripheral Nervous system/individual nerve

1. Paresis/Paralysis – hopping is normal (brisk) if voluntary movement remains

2. Hypo to atonic3. Hypo to areflexic4. Neurogenic mm atrophy

Ability to support wt decreasedShort stride (step-distance)Bunny-hoppingCollapsingFine mm tremors (orthostatic tremors)Not ataxic (not proprioceptive disorder)

Paresis: delays in gait generation, hopping is particularly slow

Spasticity: release of antigravity mm from inhibition

Hypereflexia/tonia/crossed extensor: release of inhibition

Basis for decrebrate rigidity (lesion b/n rostral and caudal colliculi

Signs explained by focal lesion?Think “structural” problem – compression or

inflammationGeneralized lower motor neuron?

Think botulism, tick paralysis, or Coon hound paralysis

“Structural” lesions - Imaging

MRI CT

Radiographs:Osseous lesions

Fracture/luxationsDiskospondylitisOsteoproliferation/osteolytic diseases

“In-direct” evaluationChest films in older dogs?Screening for metallic objects

InvasiveSeizures

On CT, bone is ALWAYS WHITEBone is black or dark on MRIn bone window CT, trabecular pattern

of bone is evidentIn soft tissue window CT, bone is bright

whiteIn a T1-weighted MRI image, fat is

WHITE. CSF is darkIn a T2-weighted image, CSF is WHITE

Normal cordHerniated Disk

•Great bone detail•Soft-tissue detail: moderate

Disk ruptur

e

Spinal lymphoma

Age of advanced imagingAdvancement in neurosurgeryGreat, but…$$$$Concomitant illness

Consider neurologic scoreLess severe signs = higher success rate

50% improve or recovery without surgeryWarning for deep pain negative

1.“Pain and Pee”pain control speeds healing times, improves

efficacy of cage rest and rehab2. CAGE REST

Allows injury annulus fibrosus to heal and inflammation to subside

Minimizes additional traumaMinimizes volume of extruded disk materialTry sedative if pet is anxious

RehabFocal spinal injections

Length of cage rest not well studiedTraditionally, 4-6 weeks (time for ligamentous

healing)Shorter times may be just as goodEarly controlled movement (rehab) may

promote healing

Prevent bed soresMonitor of UTIHome rehab exercises

Most owners enjoy participating in pet’s recovery

Profession rehab

OpioidsNSAIDSGabapentinAmantidineFocal injections

Prazosin Phenyoxybenzamine Diazepam

**Bladder expression or catheterization may be needed

BLADDER

Possible benefits:Reducing inflammation of injured cordAltering propagation of inflammatory

mediatorsSide effects:

GI ulcerationPneumoniaUTILonger hospital stays (Levine, 2007)

One study: Dogs receiving steroids had lower “quality of life” index scores than those not receiving steroids (Levine 2007)

Currently no scientific evidence supporting use in IVDD

True answer still remains